11 ms·

I often wondered i could build some sort of general computing machine if we were pushed back to the dark ages or something. I guess you have to define exactly a

I often wondered i could build some sort of general computing machine if we were pushed back to the dark ages or something. I guess you have to define exactly at what level of technological achievements we were pushed back to. But with the knowledge we have today, and without ICs (or advanced manufacturing facilities) and only "simple electronics" (whatever that would be) if this would be possible. Fun stuff to think about!

mkreis 5y ago
You can even build a binary machine without electronics, have a look here: https://en.wikipedia.org/wiki/Z1_(computer) https://en.wikipedia.org/wiki/Z1_(computer)
jhgb 5y ago
On that note, I was wondering on several occasions whether it would have been technologically possible to build neon lamp logic circuits in Babbage's time. Aside from the problem of building an air liquifier a few decades early, I don't see any really major technological hurdles there. That would have nicely solved his problems with mechanical manufacturing...
52-6F-62 5y ago
Good point! I used to play that same thought experiment with more basic utilities like my toaster with it's various settings and electronic controllers. Then I was given a Dualit. No more philosophical dilemmas! Kidding aside, it's always staggering how far removed we really are from operating on (humanly) first principles. Humbling.
- adrianN 5y ago
  There are many people on the internet researching how basic things can be made in a low-tech fashion. I particularly enjoy https://simplifier.neocities.org/ https://simplifier.neocities.org/ for example. But if you read those blogs you still notice the mind boggling height of the giants whose shoulders the bloggers stand on. Having access to simple chemicals like acids or various salts for example is huge. I wouldn't even know where to start if I had to bootstrap a highschool chemistry kit starting with nothing but my hands and my knowledge.
  - sudosysgen 5y ago
    The Dr. Stone manga provides an interesting perspective on how you'd bootstrap that chemistry kit.
    - adrianN 5y ago
      219 chapters and ongoing. Whew. This confirms my suspicion that bootstrapping is really hard.
  - 52-6F-62 5y ago
    Whoa this is great! Thanks for the link!
kohsuke 5y ago
I forgot which book it was (maybe "the three body problem"?) but there was a science fiction story where a Chinese king makes his soldier act as a logical gate and his army becomes a computer. I was like, wow, I didn't think about that, but it totally makes sense!!
- gpm 5y ago
  That is the three body problem, and while avoiding spoilers, not exactly a Chinese king.
- Sander_Marechal 5y ago
  There's an XKCD for everything :-) https://xkcd.com/505/ https://xkcd.com/505/
galcerte 5y ago
In that case, if you want a somewhat entertaining very-high-level overview of what would need to be done, then there's a manga that showed this off a few chapters ago, it's called Dr. Stone. What stuck with me the most was that the purity needed for the silicon used in processors was absurdly high, so much so that they couldn't quite do that just yet, so they made a processor out of parametrons and used magnetic core memory. I knew semiconductors had to be very pure, but it was a bit discouraging to realize just how much effort it would take if you started from zero.
- simp-in-a-box 5y ago
  Wow, no idea Dr. Stone was that hardcore. That sounds watchable! edit: didn’t pay attention that you were talking about the manga. That makes more sense. Sounds highly readable!
- deleted 5y ago
  [deleted]
- umvi 5y ago
  Dr. Stone is great but I also found it to be a bit too hand-wavy. In real life you can't just build steam engines with a small village worth of labor + a "master craftsman". Mining, transporting, and refining iron ore alone is a huge task that could easily consume every drop of the village's labor resources and still not produce much iron. Fuel is also a huge task. Unless you have a high quality coal mine nearby, you have to create charcoal which is also very labor intensive (see: https://www.youtube.com/watch?v=GzLvqCTvOQY https://www.youtube.com/watch?v=GzLvqCTvOQY). I just can't fathom how Senku realistically makes processors unless he has a nation state worth of labor at his disposal. But yeah, it is a fun "what if". "What if a super genius with the entirety of wikipedia in his brain were sent back to the stone age? Could he rebuild modern society?"
  - Jtsummers 5y ago
    At least with iron, you'd have the benefit of the existing refined ore lying all around you in a post-apocalyptic setting. There's little need for actually mining iron ore anymore if your population has been reduced by 99% or more. You can walk down any abandoned street and find sources of iron and other metals. Now, there's still the refining process (but it would be shorter from something already processed) and fuel to contend with.
userbinator 5y ago
Babbage's analytical engine comes close, and doesn't even use electricity.
kens 5y ago
Looking historically, you have a bunch of options for a pre-IC computer; there were lots of pre-IC computers. Transistors, of course, or vacuum tubes give you a useful computer. You can build a computer from relays, but the performance is pretty bad. Memory is also very important. Magnetic core memory is the way to go if you don't have ICs. None of this is going to help you if you went to the dark ages. As far as mechanical devices, mechanical calculating machines didn't arise until the late 1600s and weren't reliable for many years. It's unlikely that you'd be capable of building a mechanical computer until the industrial revolution. Note that Babbage was unsuccessful in building his machines even in the late 1800s. If your goal is to build a Turing-complete machine of some sort, even if totally impractical, you could push the date back a lot. But that would be more of a curiosity than a useful computer.
- Joker_vD 5y ago
  For arithmetic, pinwheel calculator (aka "Odhner's arithmometer") [0] is a pretty decent and reliable mechanical device. You can even give it an electric motor for doing the rotations for you and a numerical keyboard. [0] https://en.wikipedia.org/wiki/Pinwheel_calculator https://en.wikipedia.org/wiki/Pinwheel_calculator
ezconnect 5y ago
In the dark ages you can build gears. Gears can do arithmetic and calculus.
- dhosek 5y ago
  The catch is that there are tolerance issues. Doron Swade's account of building the two existing Difference Engine #2 models (http://www.amazon.com/exec/obidos/ASIN/0670910201/donhosek http://www.amazon.com/exec/obidos/ASIN/0670910201/donhosek) is a good example of where the challenges lie. It was just barely possible to do with 19th century technology. Physical mechanisms deviate from theory by quite a bit.
  - ezconnect 5y ago
    Antikythera mechanism was built before the Dark Ages, he just wanted to go back to the Dark Ages so he can do precision work by that time, he can probably build a battleship fire control system at that time. edit: https://www.youtube.com/watch?v=gwf5mAlI7Ug https://www.youtube.com/watch?v=gwf5mAlI7Ug
    - hypertele-Xii 5y ago
      Now he just needs to build a battleship to go with it!
TheOtherHobbes 5y ago
First gen transistor computers often used standard functional units - gates, flip flops, and such - packaged into small modules with edge connectors and wired together with wire wrap on a backplane. Like this DEC PDP-8. http://www.oldcomputers.arcula.co.uk/files/images/pdp8104.jpg http://www.oldcomputers.arcula.co.uk/files/images/pdp8104.jp... It's fairly easy to design a computer like this. Later TTL/CMOS designs replaced the packaged modules with much smaller 74xx/40xx ICs. You can make basic logic gates with just diodes and resistors, but you need transistors for inversion, buffering, and a usable flip flop. That's probably the minimum level for useful computing/calculating. If civilisation has ended and you have no transistors you probably don't have the resources to make glass valves either, so that's going to be a problem. Of course there's always clockwork...
- dhosek 5y ago
  We could use vacuum tubes instead of transistors. (I googled this to make sure I wasn't misremembering what I read 40 years ago in an already outdated book at the library and I was suddenly filled with a sense memory of the smell of the interiors of old electric appliances loaded with tubes and dust.)
  - kjs3 5y ago
    Yes...there were a couple of generations of what we would recognize as vaguely 'modern' computers (say...roughly ENIAC to the IBM 704/709) built completely out of stuff that looked like this: http://www.righto.com/2018/01/examining-1954-ibm-mainframes-pluggable.html http://www.righto.com/2018/01/examining-1954-ibm-mainframes-...
    - TheOtherHobbes 5y ago
      Yes, that was the first all-electronic generation after the very earliest relay designs. They were shockingly unreliable and incredibly expensive. Tubes have a very low mean time between failure, so any design that uses tubes exclusively can't work for more than short periods without breaking down - possibly minutes, maybe hours, probably not days, and absolutely not months or years. And each failure means a cycle of fault finding, which can take hours or days in turn. As a technology it sort of works in a prototype way - you can get some work done until you can't. But the unreliability means it's qualitatively different to a modern laptop or server farm. The wonderful thing about integration on silicon is that it's the opposite - it's incredibly reliable, as long as you keep the thermals reasonable.
magicalhippo 5y ago
Relay computers are relatively simple to make, and require just electromechanical relays. Some semi-random examples https://web.cecs.pdx.edu/~harry/Relay/ https://web.cecs.pdx.edu/~harry/Relay/ https://relaycomputer.co.uk/ https://relaycomputer.co.uk/ Main issue is memory. Takes a lot of space to make any usable about of memory out of relays.
deltaonefour 5y ago
The first computing machines used relays which are electromechanical mechanical switches. Current would flow into an electric magnetic and it would magnetize a switch and close a loop thereby switching something "on." By placing these switches together into different configurations you could form equivalent logic gates. Sometimes insects or moths would get stuck in the relays which would screw up the system. This is the origin of the word "bug." Prior to incorporating logic into electronics, computing machines were hand cranked or motor cranked gear machines. See: https://www.youtube.com/watch?v=fhUfRIeRSZE https://www.youtube.com/watch?v=fhUfRIeRSZE. The YouTube video literally is a hand cranked portable calculator. The world you envision has already existed.
- agalunar 5y ago
  The use of the term "bug" in engineering predates automatic computers by nearly a century; the Wiki article [1] on the topic gives a pretty good summary of its history. [1] https://en.wikipedia.org/wiki/Bug_(engineering)#History https://en.wikipedia.org/wiki/Bug_(engineering)#History
- deleted 5y ago
  [deleted]
- hypertele-Xii 5y ago
  > The YouTube video literally is a hand cranked portable calculator. It can even do square roots?! That's amazing. And it fits the palm of your hand! Now we're down to specks of sand calculating so fast they melt without cooling. Seriously wtf.
Koshkin 5y ago
No need in electronics whatsoever - mechanical computing is a sufficiently advanced engineering discipline, as, incidentally, is fluidics! https://en.wikipedia.org/wiki/Fluidics https://en.wikipedia.org/wiki/Fluidics
95014_refugee 5y ago
Then the next question is; what would you do with it? You need a source of problems to solve, and until you've bootstrapped the rest of society at least to the point where something like high-resolution trigonometric tables, desktop publishing, high-speed accounting, (for example) are needed, the effort isn't going to keep you fed...
- tyingq 5y ago
  I agree it wouldn't be high on the list, but I also imagine there would be practical needs. Like command/control. So, voice only radios first, but some sort of messaging that doesn't need a live listener on the radio would then be a nice next step. And that could be done with a simple computer.
- kjs3 5y ago
  Calculate ballistics, like some of the original computers were created for? Never too early post-apocolypse to start the thinking about the next war.
mburns 5y ago
CollapseOS is a z80-based forth that is targeted at bootstrapping computing from scavengable components in old electronics. https://collapseos.org/ https://collapseos.org/
Teknoman117 5y ago
I mean, you can apparently trick swarms of crabs into being logic gates. https://phys.org/news/2012-04-scientists-crab-powered.html https://phys.org/news/2012-04-scientists-crab-powered.html

mkreis 5y ago

You can even build a binary machine without electronics, have a look here: https://en.wikipedia.org/wiki/Z1_(computer) https://en.wikipedia.org/wiki/Z1_(computer)

jhgb 5y ago

On that note, I was wondering on several occasions whether it would have been technologically possible to build neon lamp logic circuits in Babbage's time. Aside from the problem of building an air liquifier a few decades early, I don't see any really major technological hurdles there. That would have nicely solved his problems with mechanical manufacturing...

52-6F-62 5y ago

Good point! I used to play that same thought experiment with more basic utilities like my toaster with it's various settings and electronic controllers. Then I was given a Dualit. No more philosophical dilemmas! Kidding aside, it's always staggering how far removed we really are from operating on (humanly) first principles. Humbling.

adrianN 5y ago
There are many people on the internet researching how basic things can be made in a low-tech fashion. I particularly enjoy https://simplifier.neocities.org/ https://simplifier.neocities.org/ for example. But if you read those blogs you still notice the mind boggling height of the giants whose shoulders the bloggers stand on. Having access to simple chemicals like acids or various salts for example is huge. I wouldn't even know where to start if I had to bootstrap a highschool chemistry kit starting with nothing but my hands and my knowledge.
- sudosysgen 5y ago
  The Dr. Stone manga provides an interesting perspective on how you'd bootstrap that chemistry kit.
  - adrianN 5y ago
    219 chapters and ongoing. Whew. This confirms my suspicion that bootstrapping is really hard.
- 52-6F-62 5y ago
  Whoa this is great! Thanks for the link!

kohsuke 5y ago

I forgot which book it was (maybe "the three body problem"?) but there was a science fiction story where a Chinese king makes his soldier act as a logical gate and his army becomes a computer. I was like, wow, I didn't think about that, but it totally makes sense!!

gpm 5y ago
That is the three body problem, and while avoiding spoilers, not exactly a Chinese king.
Sander_Marechal 5y ago
There's an XKCD for everything :-) https://xkcd.com/505/ https://xkcd.com/505/

galcerte 5y ago

In that case, if you want a somewhat entertaining very-high-level overview of what would need to be done, then there's a manga that showed this off a few chapters ago, it's called Dr. Stone. What stuck with me the most was that the purity needed for the silicon used in processors was absurdly high, so much so that they couldn't quite do that just yet, so they made a processor out of parametrons and used magnetic core memory. I knew semiconductors had to be very pure, but it was a bit discouraging to realize just how much effort it would take if you started from zero.

simp-in-a-box 5y ago
Wow, no idea Dr. Stone was that hardcore. That sounds watchable! edit: didn’t pay attention that you were talking about the manga. That makes more sense. Sounds highly readable!
deleted 5y ago
[deleted]
umvi 5y ago
Dr. Stone is great but I also found it to be a bit too hand-wavy. In real life you can't just build steam engines with a small village worth of labor + a "master craftsman". Mining, transporting, and refining iron ore alone is a huge task that could easily consume every drop of the village's labor resources and still not produce much iron. Fuel is also a huge task. Unless you have a high quality coal mine nearby, you have to create charcoal which is also very labor intensive (see: https://www.youtube.com/watch?v=GzLvqCTvOQY https://www.youtube.com/watch?v=GzLvqCTvOQY). I just can't fathom how Senku realistically makes processors unless he has a nation state worth of labor at his disposal. But yeah, it is a fun "what if". "What if a super genius with the entirety of wikipedia in his brain were sent back to the stone age? Could he rebuild modern society?"
- Jtsummers 5y ago
  At least with iron, you'd have the benefit of the existing refined ore lying all around you in a post-apocalyptic setting. There's little need for actually mining iron ore anymore if your population has been reduced by 99% or more. You can walk down any abandoned street and find sources of iron and other metals. Now, there's still the refining process (but it would be shorter from something already processed) and fuel to contend with.

userbinator 5y ago

Babbage's analytical engine comes close, and doesn't even use electricity.

kens 5y ago

Looking historically, you have a bunch of options for a pre-IC computer; there were lots of pre-IC computers. Transistors, of course, or vacuum tubes give you a useful computer. You can build a computer from relays, but the performance is pretty bad. Memory is also very important. Magnetic core memory is the way to go if you don't have ICs. None of this is going to help you if you went to the dark ages. As far as mechanical devices, mechanical calculating machines didn't arise until the late 1600s and weren't reliable for many years. It's unlikely that you'd be capable of building a mechanical computer until the industrial revolution. Note that Babbage was unsuccessful in building his machines even in the late 1800s. If your goal is to build a Turing-complete machine of some sort, even if totally impractical, you could push the date back a lot. But that would be more of a curiosity than a useful computer.

Joker_vD 5y ago
For arithmetic, pinwheel calculator (aka "Odhner's arithmometer") [0] is a pretty decent and reliable mechanical device. You can even give it an electric motor for doing the rotations for you and a numerical keyboard. [0] https://en.wikipedia.org/wiki/Pinwheel_calculator https://en.wikipedia.org/wiki/Pinwheel_calculator

ezconnect 5y ago

In the dark ages you can build gears. Gears can do arithmetic and calculus.

dhosek 5y ago
The catch is that there are tolerance issues. Doron Swade's account of building the two existing Difference Engine #2 models (http://www.amazon.com/exec/obidos/ASIN/0670910201/donhosek http://www.amazon.com/exec/obidos/ASIN/0670910201/donhosek) is a good example of where the challenges lie. It was just barely possible to do with 19th century technology. Physical mechanisms deviate from theory by quite a bit.
- ezconnect 5y ago
  Antikythera mechanism was built before the Dark Ages, he just wanted to go back to the Dark Ages so he can do precision work by that time, he can probably build a battleship fire control system at that time. edit: https://www.youtube.com/watch?v=gwf5mAlI7Ug https://www.youtube.com/watch?v=gwf5mAlI7Ug
  - hypertele-Xii 5y ago
    Now he just needs to build a battleship to go with it!

TheOtherHobbes 5y ago

First gen transistor computers often used standard functional units - gates, flip flops, and such - packaged into small modules with edge connectors and wired together with wire wrap on a backplane. Like this DEC PDP-8. http://www.oldcomputers.arcula.co.uk/files/images/pdp8104.jpg http://www.oldcomputers.arcula.co.uk/files/images/pdp8104.jp... It's fairly easy to design a computer like this. Later TTL/CMOS designs replaced the packaged modules with much smaller 74xx/40xx ICs. You can make basic logic gates with just diodes and resistors, but you need transistors for inversion, buffering, and a usable flip flop. That's probably the minimum level for useful computing/calculating. If civilisation has ended and you have no transistors you probably don't have the resources to make glass valves either, so that's going to be a problem. Of course there's always clockwork...

dhosek 5y ago
We could use vacuum tubes instead of transistors. (I googled this to make sure I wasn't misremembering what I read 40 years ago in an already outdated book at the library and I was suddenly filled with a sense memory of the smell of the interiors of old electric appliances loaded with tubes and dust.)
- kjs3 5y ago
  Yes...there were a couple of generations of what we would recognize as vaguely 'modern' computers (say...roughly ENIAC to the IBM 704/709) built completely out of stuff that looked like this: http://www.righto.com/2018/01/examining-1954-ibm-mainframes-pluggable.html http://www.righto.com/2018/01/examining-1954-ibm-mainframes-...
  - TheOtherHobbes 5y ago
    Yes, that was the first all-electronic generation after the very earliest relay designs. They were shockingly unreliable and incredibly expensive. Tubes have a very low mean time between failure, so any design that uses tubes exclusively can't work for more than short periods without breaking down - possibly minutes, maybe hours, probably not days, and absolutely not months or years. And each failure means a cycle of fault finding, which can take hours or days in turn. As a technology it sort of works in a prototype way - you can get some work done until you can't. But the unreliability means it's qualitatively different to a modern laptop or server farm. The wonderful thing about integration on silicon is that it's the opposite - it's incredibly reliable, as long as you keep the thermals reasonable.

magicalhippo 5y ago

Relay computers are relatively simple to make, and require just electromechanical relays. Some semi-random examples https://web.cecs.pdx.edu/~harry/Relay/ https://web.cecs.pdx.edu/~harry/Relay/ https://relaycomputer.co.uk/ https://relaycomputer.co.uk/ Main issue is memory. Takes a lot of space to make any usable about of memory out of relays.

deltaonefour 5y ago

The first computing machines used relays which are electromechanical mechanical switches. Current would flow into an electric magnetic and it would magnetize a switch and close a loop thereby switching something "on." By placing these switches together into different configurations you could form equivalent logic gates. Sometimes insects or moths would get stuck in the relays which would screw up the system. This is the origin of the word "bug." Prior to incorporating logic into electronics, computing machines were hand cranked or motor cranked gear machines. See: https://www.youtube.com/watch?v=fhUfRIeRSZE https://www.youtube.com/watch?v=fhUfRIeRSZE. The YouTube video literally is a hand cranked portable calculator. The world you envision has already existed.

agalunar 5y ago
The use of the term "bug" in engineering predates automatic computers by nearly a century; the Wiki article [1] on the topic gives a pretty good summary of its history. [1] https://en.wikipedia.org/wiki/Bug_(engineering)#History https://en.wikipedia.org/wiki/Bug_(engineering)#History
deleted 5y ago
[deleted]
hypertele-Xii 5y ago
> The YouTube video literally is a hand cranked portable calculator. It can even do square roots?! That's amazing. And it fits the palm of your hand! Now we're down to specks of sand calculating so fast they melt without cooling. Seriously wtf.

Koshkin 5y ago

No need in electronics whatsoever - mechanical computing is a sufficiently advanced engineering discipline, as, incidentally, is fluidics! https://en.wikipedia.org/wiki/Fluidics https://en.wikipedia.org/wiki/Fluidics

95014_refugee 5y ago

Then the next question is; what would you do with it? You need a source of problems to solve, and until you've bootstrapped the rest of society at least to the point where something like high-resolution trigonometric tables, desktop publishing, high-speed accounting, (for example) are needed, the effort isn't going to keep you fed...

tyingq 5y ago
I agree it wouldn't be high on the list, but I also imagine there would be practical needs. Like command/control. So, voice only radios first, but some sort of messaging that doesn't need a live listener on the radio would then be a nice next step. And that could be done with a simple computer.
kjs3 5y ago
Calculate ballistics, like some of the original computers were created for? Never too early post-apocolypse to start the thinking about the next war.

mburns 5y ago

CollapseOS is a z80-based forth that is targeted at bootstrapping computing from scavengable components in old electronics. https://collapseos.org/ https://collapseos.org/

Teknoman117 5y ago

I mean, you can apparently trick swarms of crabs into being logic gates. https://phys.org/news/2012-04-scientists-crab-powered.html https://phys.org/news/2012-04-scientists-crab-powered.html